SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f724f750581d102e166d22d0e72896f47d552f1bb087994087a88a0812704044' 
  AND token = 'ArG7pnMJlrosvlxtuDV8y7DhzhdTu/7aZ11sZ0gvgc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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