SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e5525a0c24adbd73eb8251954b2d44262baf45eccc5bfdb623b6806a1b958a2' 
  AND token = 'pvcuiIExLvhkjQ7gr4qL97umbYjbSM0hyft4LYUIWgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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