SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '491ea439a1cd6ceb7ceb7cce2c8f0e50330d4ea30c8c293eae9b14c2b866a01f' 
  AND token = 'tS/HJyqGxGYeoXM5PeQtjckFUhBlS4EZnp1lfLPsQ60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}