SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4cf81e632c6d4a1864b76553812c85f550031f498f6f7ca2bbc5c6e97eba3862' 
  AND token = '/IEzsRV+g1jfR0/0v6dFycm94qz5iRVm4nDbOLouSj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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