SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2950dc19b9788c7f8a845167ff0c5265d2c1900b4e144242ebe1ff365893c79e' 
  AND token = 'mG01pFC1NKvjZYTRgjRohTamelYX4Xk+Qq4fXun3s28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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