SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae0a5857e24aa7faabe3e44d0e5269e7f09f25b2039f90695f8e5735c3b3359d' 
  AND token = 'OLRYeyAm48a7vRzJ5whhvuGdIMn/DeUR/wD3U1CNU9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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