SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fee112d0219b088b9e8bc691c3a1b7b016cd473a1aed7ccccdd88b109a814e13' 
  AND token = 'z3TzIpbDdHFcKT2WrCa2mgmDPbG5ykQePtyBT9HRDlE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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