SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68adec11c6fba1e973f85f49c7f228fa985aae58df5051ff2b934fd85f589b2d' 
  AND token = 'RFblr65kutjbU3Fc5Qi9GiWULP4jjHjfcFjTfBSnR70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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