SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a9b727e68ad5bd55f01ebda46df47d266279fb531034e321056f9ebe5f4989a' 
  AND token = 'J7Czw5SKsRTnVIrJ4dEfqjH389xfoO6D1xCqbR+M9wk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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