SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4009b3ce3046d727be84a767889313c5e5c5dee5c66577780dead188537ca8ff' 
  AND token = 'Htx9k8rT3GYGWyWvnl+BLvhoBb5P6edo4FJByrRmK3Q=' 
  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"
    }
  }
}