SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41f68ca9b56d57ce62a64cf6192413496e555ee0df1d767fc9f7e50e22328005' 
  AND token = 'LJjPoIxPSTpzVov9SdedVUYO8lNCCQjPbc5PdXuFUtA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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