SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cb9e6de5b38a119020ac18c88baa0e8a39546cb78ce2595958b3cc8a0631130' 
  AND token = 'tHRYt6db8uBJ+cgVwtrqn8E4F7mItoOo+yOFzlKLJrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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