SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bad12aab8cea5fb1bb4a91f8838b1cc6aa6d34493d63de9a41d3820684de04b' 
  AND token = 'IUkZy4qtzrRGK3wSctTNevHisiqQdeQh9zaH46VnNXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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