SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '805db4d786fbec5f59fc65da30afdef0f29ccbca6847e18084476fe375375f85' 
  AND token = 'uSc29A/kUIk/riCJDJSZA/2zmO4499ZLH17dwW6MlH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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