SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49a4b8cbd55860db8733651c2a051e7e8473c4f0a0422a1598cb3c08b82b47d3' 
  AND token = 'v5FyfRHn9FWkK7UKOX46g4d3vJyQVDOaY8NinfVBjqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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