SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5beda048abd1c54b0a64c41329016409fe1e8dec709ed4c131074a934332ae65' 
  AND token = 'jvEYrXeIdjO3g0w8ZmJUh+wCqC/NJ0W4wxVODWQmQ+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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