SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0b6f2e3bf7326e2dc9bc4d4c5068c95a5013b6e0b27d4784add97d9a4e94190d' 
  AND token = 'cUWh9LmCFUuTW0gb4HCJGgbCi9SqnjmqNhik5V+iYR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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