SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b5034b5f5e5ff91947b1f8f4d4264c83a2439684f6757825df1293a6fd13ff6' 
  AND token = '0qnFwYe8EN7lJmnjipjMpXUEu3yV1Zaq6aXBcH25Zqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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