SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0715be4cfd09275ece67de6e8c604f504e17d48aa0160e23473405fb5325daf8' 
  AND token = 'ScTQ3AqA2OdZ03SW/um/4J29v9o3xSqZSIZ6Px3NBKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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