Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6a7c4ff5e2a96400e1ec8091fc5c5aea82e7a0493beedf2c9e9383c8a9f73c5' 
  AND token = '/z+aMkdKvvi0nlHY23PCxou2UAkhzN8ok/kvSAPm2Lk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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