SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '122d45d2b8345ade86d66da808c1a5afac015972a2fc1d724c5a5b6160c59984' 
  AND token = 'b4tNkuuhsNyWupuqu6H6BKomZxCre0HRDq7s7Q8/oA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}