SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7fdb50e6c2053a2faa695db187253184a352af8266a103673e99e4910e7b01da' 
  AND token = 'dM8J/ejlUEoLT7LfLFR8NztLkXU1ihQf662FtFENtMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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