SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d9fcc58bef06823e354c1678b63055fdb9a4f77351cb2c6a9f21eb68815e831' 
  AND token = 'tVjBBL1o/wa6rXRW8KGhTpXAYFQAyGIQrLLOs7cdTvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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