SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f11486c2b2479b2812131bf7b1c534094f3171bb78ffa31d168476d0fd47d411' 
  AND token = 'NXhVaHDhGAt25Gl59egt1f+w5m1ElOPZDYOgh1pab/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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