SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3da15d5e270c2f9936cd8745545a055680a9362a6c9a7f27af61975d288355e3' 
  AND token = '97gN0hXcP1dJqkJEDNA7qQZBKdY5bbeBrFBkvnP7mYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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