SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7237c155ac1cee0e939233d237d4cd28633fc454169788a4e73d83f6e2307277' 
  AND token = 's5QmhdyGgQ1WgubAFTmuisRdLX07Xsh5ZVRcUJr6iyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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