SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a5f9c1899ff3726bc5c8ef4abe316e14700cf4f46dc10d0d772037784bc4acc' 
  AND token = 'xoMJflHC+HkiKCC1P7Q5fJI0VCc/ug/dl8PHyM+xlpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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