SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0b8349c1cb969cd759ea8e1c94e0d988c50e72aa11324034c3263d6726c57fc' 
  AND token = 'yVBPWvraqJ3ncuQvHYGIduhBxH6a/QNeUWmYJEpL5Y4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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