SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '81c42f5f4542adf91c7026db728999c3154a1c9a274c96309e984fbbf0872e98' 
  AND token = 'zTJxvAd5sfpPhjw+vMy1qHf/+Hi4Y2+M9isYJV7hc40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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