SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '601e51d2f977ea922394a7c3b8e37974cbe8206e805cec72ea5b9774124a1708' 
  AND token = '9kszsFwE9I0sC5WZGb8Ht6JBtZaTCqYoJArqPKZFV+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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