SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa9e28bf14bf8564ee28de41450c47276cafb13aa8a9d97c0b87e86f7e930a74' 
  AND token = 'wxZ1eEK5zn+wjXcE+B6W/g/G/CB9Ad3fXos3/iJhhs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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