SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe5e7fc1c1b04fea7e028d9579dc358049811841023a237602e1d6196279275b' 
  AND token = 'VxwvAS7Cq0D0puljNrhjkA4w+gUgqrVDM1R4XM/OFbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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