SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e8359977cf79dfeb7c9833e6c263d076337e27c8365a068be8d3d0e7d2704aa' 
  AND token = 'hzE6ZQFrIS2rWImkMQzzfbHzkcofX4JIS3bKuzRYHIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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