SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7f1574697db3d9b2e5747891dc220d194d984c3c9ce0c1dcc5f31feb0400f9d' 
  AND token = 'ojdyLIhFxjOzUxpBoMoJHVvSOWxKdlhsLga54PvFr/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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