SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4651a054b0606aa7e7fd57ed4b0310e448f34cbf7500f7648ecbec8df9c2867f' 
  AND token = 'U7vFwuWxzA//wiVaLnb69/C7j4Wo18qtpezGbUffFqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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