SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66583e2f29d0849f16b98b0d0033ea3c56770d2231e496c1af635c8d2eab7d42' 
  AND token = 'NYfORgfljVqKM5T4vJNM+1rigdgKA2Cj9HUPTsU7XaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}