SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afe722bdddb552952ce2fa841c2ecb5d9777fa41c82b619d179f17b36ab40a37' 
  AND token = 'ROt7c5tLKS2IrSbzlKvW//4KWmdLbVhlPTf8sybePnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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