SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1754993f662ec1f7e944e95872fe1dd4fe284f1b8ba45ec0089cd7d74f701b68' 
  AND token = 'EmuM/mcju9cN05fYDge/3sFDcON93DPUeYo8DTyX1sQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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