SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c6b28c16b4b9ad7f3bd3149c190dbc5a6714dfa25bcc00abe681d65560cdcc1' 
  AND token = 'B722IQawSZjEbbjeRXwzH3+AdNMmfOfQK+MkoAwRapQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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