SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '513e4f95d203841b3acbd926724eab8b7869316e88238c6de5ea88d4f5131316' 
  AND token = 'HtRIGoA9deXf/g8cnYGBucmFzPAmpH6QlyIcRapPNFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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