SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '718d604d061ca0da148cf17b729d87f8bc5a8c7665d7e6d5615d3496d8d0a45d' 
  AND token = 'G7qNWgxMLPZW+RnRvLsAQVvXDAY3vNZ0QNwHAIXY0x4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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