SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c9cf1e26e5cddb5d2267a01bcf2bb5c7000602452e5b869b5e98928bb75ee0f' 
  AND token = 'IjUWzUFxHGDRTabJgLK1bMePefOX2tvXCOCxOmh/Wuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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