SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3281c4b97738c63fa6435876293f82be5b9ef008648fba3a9a12bc8b28bbf90e' 
  AND token = 'YvIr3c8DlVmBviPkPJguLdag21tdUUYrvOnEI+2UzXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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