SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5367daf240ad41069afc4b1bf0e54d32097b97165a7dfe0d6e2a178a09899890' 
  AND token = 'oQ0N/NgKAHb7ZMOKY0UnyYZnDIpBDqzf2gJj12nvsAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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