SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2fb7b31e3ced504ed036cb1711b961085a7a194fbbad53f00e4863ded401ae83' 
  AND token = 'LxbL0e023pxytWGOSJICxGsnYQu/2IiBEAfjjHBd4tM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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