SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ba758f4a17ef1713bdeb543e7c1c9b1245d5454976a942a1693b2038ce827d4' 
  AND token = 'EsRoZW5DtKncuhOoTZ+eKKLGB80khJPTF9/YZbPv+Dk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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