SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c38193991f9ab7b47e74f3d038e7418aa971e8f8da5f9c70cea091b7059cd972' 
  AND token = 'L7UDJXbJLAojB1cba/OYkrys/GujXAV5OyxN7VOU+ds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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