SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4d1c2f89c1f3c0ca2e723ae7fac9bc41bcc1527de1f81aef4e456c4c3d484fd' 
  AND token = 'pJvy8jE69oDg7L4C5VrkLm+GjRNhOYvV+lfMzobmwRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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