SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '373da70be9828d3d04ebfc3e09b6bfb438b5e140dadb73db8f9415982d0ece21' 
  AND token = 'wC118AZTdr1r6wa0FVoeCYQWa9f0xOAYteP47E114eI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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