SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e38c736bc86ca3421eb833f04214765cb147393153971918fbcbbe77ae209ea2' 
  AND token = 'IHkeUDj3ylYCffcNRuH9VmuHtnRQc/wW+SL4FX3QNdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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