SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0aaf524a1ac12eb46448ce388e1940fceca47e090a6be3a0ff01759dec990beb' 
  AND token = 'mgwE6qofyNpwl3l50ihr8VUrBcbDpixAa0TuFYF32GA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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