SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b3b4e13c65c5ffee820fe5a585efcba2567e4301880d8fb963e191cd8dc62fc' 
  AND token = 'uHsHnE4wlVs0JlUot0tTVoDFLqUvbDXXXnMIL41A5WE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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