SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '044ebcfdad2d9bc9e72087565705d60a0942df71e7080a504668f7c1a9837f14' 
  AND token = 'veL6sictyAatjDU0iQVU0Fynnj1TO2EgYXSGnoTz+BI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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