SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e3a34724ceaa2d6791750bba8611b01ba0ccda495421df81adfe0a6f0276edd' 
  AND token = 'gLNPqOs+0PBVRDmQVqne10ZPHlia2DI+9CI4EOnozpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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