SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f8449cfe54e155cc7974a863c69cbc1989dcfca3522f56271241f158b206e46' 
  AND token = 'hx+P6ILx7QvC6EdOUBaWzLBt2sUEYmZOV+pEbjVnSjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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