SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ae368daa3d490b33f7652a8fe36cbc2c7a7d9e3bd48820c6291c711f1b3b980' 
  AND token = 'NsoRwEKnOFWCFc6KmlXjNWs36hIzM4ceODT8Y02xy6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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