SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb6b5e461e23d118a0a2e53e36f654702b408ebb33781a6527d4692b00b4253e' 
  AND token = 'IaZSljSVn66hxIkEjcukBwHyTAlTlEFrl/Z5ViAPqyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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