SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b38a6e08788593b576b5587006ecb0400650aae8f7dcfe9509ab2cc13fd0acde' 
  AND token = 'TY+qJ13Rs9KMaykD8BkOhTwqsgQiMHw5Y67O0hdUFcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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