SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a71fa66aa1c7fc6c9dba78a095abd9d64f7c7dfac8404a3c14f1022cb1d5c18' 
  AND token = '7e7GrFIUMh7quT0mQe2V8L2icH4Ykos00RFrm9Z6Gf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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