SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '400efdd5c9ad637d1197409fa7f18a4f96dc318de1c74ca8a5d5505f28c53c46' 
  AND token = 'FE+rR+lu3q3Fu6jPq2a94kSa8kwdBbmLFzmwjhyFYHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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