SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9a096b01ca9a13ebd1f7e27e437bf90f75107086067dccab208327c28e9d6f2' 
  AND token = 'JfbCU+vlA6J73f+9zapUA8eOQKzHk4lvNPosj413HgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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