SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8309ce58babd5b8f32e10a810cea558dbff70225ed3f00a6f80c053e9966281f' 
  AND token = 'kFLf307jHIwDYa7Ogx/AH/FdMTzSvJR14Ub8HtY1VY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}