SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14cdc24698a13dd1bd209cb737f51d088436b005906d160002b0b2ec71e0e532' 
  AND token = 'xDX27/txRZpeSj2IUKEXUwbbU3QplmKT+ePlr9cuVPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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