SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cee947cea33e08c2202b16d1c35bcd61968b39e2e4553a89959371a9ef1ac759' 
  AND token = 'HhyjV6YQNPLQt7Y3f40QtwZSDNOnkUAmlvQAs6daOL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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