SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '786868d2aa13c6dedf72eb4583d68c4cf5fa85f3e94c39f1243550f81ce3a5ff' 
  AND token = 'yRsA5YnH6CyW8MvZDYDnzki3d1uswwehJ4r6pdYRkl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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