SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '59ad9b5f24c23ea3dbd95df19b67b7c513b06f6ae76b941ed678f5b6c5b9d7ab' 
  AND token = 'POXU+ncz2cL5bNzejXGGh9QaGCwN0VSrfv/YjBKPWl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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