SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6172aacc78da249b2308eb8741fde53c673245667cf97f478d757cf9813469b1' 
  AND token = '/pbWXlxeJ3ZTPu9bmvvdBr6HU8yaDo9moQzgvYwobA4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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