SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f984c5c46a5f1eb0d4bd7c1903c0475f8bbbd5d734e63cb354b41481816d97d' 
  AND token = 'J+seW1WK/EAPdWhGmHvx/Is/BxguDjbDF9kMfYJXPPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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