SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d1e5ebbe2a92d702c9a863bcd729f6a65989da1b1181702f4cf76b0e7462cb1' 
  AND token = 'x2W3c1bZePI7JCWpDwpVUbHOVI7mqdy7FKdCrYwIiCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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