SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7c25c4cb561cce3f02603446d4ec1d9679e648e1ac15bdbcf939db3fda61706' 
  AND token = 'cOFscyJNYn04NUe8aYZyJaLpOXE2EUPpVsfgGyPQE8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}