SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae19d3bbe79c8f7b60b974a0af7a1349a6460001d7eb30e23e6159f84fa0e949' 
  AND token = 'RSf4lfNG2JfG9gdCVv90BKd29TqbBRbflaXjgMn0AvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}