SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54f2bbfd6d24d367aec8cf17a23f5ecf3464b6c0abc90a9b7c2f79ddbf72014a' 
  AND token = 'wSvuaDuZpa5qJWP+yF5RAb18Gg2pNvoLUsGQlf/5ziQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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