SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38c7407f9ca7022ef260bbf2bdc217ced4c1cf97eb6c5aa0af8eb3016e26cc0d' 
  AND token = '759mHrb5iSn66Xvb5kapU/AuAOUaSLgWn957OrK+hVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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