SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '84740b23d4ff1b46360374a712341715265bceb72f3ba74cb4dcd6842c2f2e15' 
  AND token = '14pDv/RpILdZONx6ZCs3yZAZhyS9AvYsAzllsS82g3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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