SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de7d262b4f41218874c34081c49cc1eb1a8dc9a71749c2372575d081ce408d61' 
  AND token = 'JfstZ8YNkUfKwGYSsGhNzflVuFIUHxSAuNnSyFtY9a4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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