SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d0a79572d332df111bb490b4cf458142ff5857e1c2bf9819e8c582747dc28d3' 
  AND token = 'eWG0RHmIsG4wsSO+6SLwPA4ZkvEc/UJbhHRTni+rlgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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