SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6eaf5433d232dca436c5b79061a2ac244a602bb0bb9d3e678f890e8d08b97fa9' 
  AND token = 'CY3sKamGDNJxNql4fqlHK5/b8aY8qZvKUqhYTIXnJBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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