SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33855e88b504a189c69721b1b4bc2f42a16ad0805c601b57470588264f633983' 
  AND token = 'UaijphK3n2mOKxA3o6iU4B1uW7dkjt+nKM23xUDYLgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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