SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f91290c6baf5f706c8736044795f7d8e334a879fb865cbd6414da0ee6f7faaf' 
  AND token = 'dEc5ajPanwSAuyqozq1AAi1Wx5H6j6MYsbVl6E2//cc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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