SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e4a994eb208faad19c0d8e5bad4b094ba439169ffe860503e4829961b478f426' 
  AND token = 'pcZntltlUK1uDy0YGhi0URclw8efscMFxZVRdtWLKqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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