SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f9be54d83073d17bada9e30408a78d12554e264ca97b4a6eebaaab13de38e4e' 
  AND token = 'On81gxByOnVG7f7EIpZyY+oCu0xNjtmGus02GhIGdI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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