SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94fb6f3c71e55f1fe133c0e370a9c07db37f88db9c05ba1e13b67e83ac303927' 
  AND token = 'vOTnAUGdqrwL/5ljkzJLT6j0zndGSsGO7zhmfF+MJLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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