SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '754492ef38814b27951fb32683a90767bf1267ca79b3e99aa1c332cf1d0eb95a' 
  AND token = 'BwpqiQNPWlf23LNfSGIVz/wxonm2B/5uMrZG7oodha8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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