SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91c27808861d5e518a5bd40f027751c2dab45191ae5a8f00c3cef20b6c66234e' 
  AND token = 'ncBG5Ks61oG09p9QjdxCafftdBDN/Ayp47iIapF3FJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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