SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d3e3a7ef811963b6b0cfc7412e02af59d9b606871055de299a399f4fb4e07d0' 
  AND token = 'ZfhcDM3yznuAmK+wLT+8u/i5gXjAKggUNo7NyGJqKAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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