SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6aa13449fb8d5094790d33402ffaa8535a23f8ecaabae83b08e9012fa27d325' 
  AND token = 'Te47u+jgSX6Trd/fsVpIMKeCdovzjLERSBBJb01Aflw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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