SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2522695a9a9595cfe625d629b12c6716a9a8d43e13098cbc78d3d1d49906f696' 
  AND token = 'JrmY+XNsKQNPDoJeSXEjAoiAVifkovjn3bdGqtv33SM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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