SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b68c953a8db240b36597b30cf098ffe015621d940e1fa861fe0f96037b66ace' 
  AND token = '9BVMY/IhHn/pR35gvIQI5CNCK5z54O8Vh0LTlDBXBlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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