SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08cf5de42c297772a1e7eab87075cf601151545e5b83e2a8807b5e38d8dc394f' 
  AND token = '2i+auOpj5c5tvQwVY5XVu6/TuIUN4G1JE32TjqgKvLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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