SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ee8b687db3ed36422cf21759fa72bd1e330da0b0936d23f5b63c6d1404547ad' 
  AND token = 'uZTAx6bfNwKSHk8BD+rTs88hFoewVtwXG/S+dMhl0hw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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