SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63282d57f12c253aa1193fe7545cfbbbff6a99910a5c769c6e57ad2045a81a2a' 
  AND token = 'gQs3TVhajDwKj0DPOu7/jofvVlzN243WwpNwDOKU+t0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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