SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b53d36eff3b5ad8b6391c5e8d61ab71d07566b57485880760d02a5a1fee819b' 
  AND token = '0QLcNBWXVzvmThp1842VkGiBdVPGcDeeEzNNPWrUimg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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