SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73f3d2a635cb021d33549e8917b21f4152cebe1f9b9f7fa1c227e2d6f4f03c5f' 
  AND token = 'RhfKO+zHkBjFFAkA25q8jTHm5wlO5zV8sDfJvXlPWMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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