SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '554e148c00bb6f0231fbbf8898019aa62751a05792b911616abaeace2b379cbb' 
  AND token = 'vWj4PLZX2+o+JbZJNyMQMxfJ+p9vVb0XefaWuVDXmjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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