SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ba0e1f84e73204b9a472c5ccb56bd2ff678baabf578298a6b2a3978948fc527' 
  AND token = 'zX9VqFj83xOGKJA5KdejI+h/eXV5Ft1UEgjQ0yGVvlc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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