SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e0285f7d348601a90c4d31e9a48b2f0be40178845feed2b03f721d50e930e41' 
  AND token = 'sS6UhGlAjbHkTP53EizAvOXa0gTSJhefUeLDzETt++o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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