SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b2a9b04b52c082d745f04e3c17b853c24d81a390ead26d5482ecf07e636c94e' 
  AND token = '/vqaEAeDeFVeaWl6Nxh3Rs/FibvV7wxOpUyROCIEaMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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