SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f490afe4525ceb0820f8b76d6a157dc3418b883aa60307b4dad25dede3158c5' 
  AND token = 'hD1DkYyzBEDeoKBjCbPtudXuWZXungsDtzdWjgriKfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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