SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d7fb48fdbc677ebf806906601eb59df59542761d1c55a98d4960dcaadc1ac68' 
  AND token = 'M2rprDBhFLNOMQwWNeI63JT2ATBFmAr8e7u5mT7O/5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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