SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c52acda667ee86878437d04e6f05d6963eff12aa3381be69ef4007c526ab9a69' 
  AND token = 'q+6rPYkGWEBKt0qNmuCTmZBbjwWEqIdT5mstvYHOkzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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