SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b8ecea00c906fead16905d67e8745245a325c899e72a9bd90c87137947270ce' 
  AND token = '9L1hw+VrO/7RGCJmfJK2u76MzcvvH0qnqnFK3oOx8B4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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