SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9f6528a93a413bfb4679624629a841e7e853cfb5c886fb142ca2de8320fe3d05' 
  AND token = 'kIXmx0YJroVQK/oU9fZmoZFOmbouVux8UbUYuo2ZqB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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