SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b9acfce85da698be75298701b2b5599438c0fd470b9b3decfb804c5fd92fe62' 
  AND token = '0QZdjD5Im1ehz0oyDJBMu5K2icWxtDMR3YYirfrE3Vo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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