SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f2f7c7ae6f42f0ee4ecc3936d594170add6d337403cd268cfc99264fe678790' 
  AND token = 'fbOcBT/dNvwZX/0FmemzJBIDhKySJil8Ljbx7eZ1caY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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