SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bc1a8320225fc3101c8e58109a3fe5f0ccbc1a3d8206a7059deba34c5c787b9' 
  AND token = '2DfedkCIeyUKa2LEtqyzWAULlJqZ7mQxUuWrwm7SCbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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