SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37976ff83f6c7a524aff3e20a8c7b55d84b589eb026ebf448ad353f8a97f236c' 
  AND token = 'YfGN05ht+u4kWNenhcb3U32PU8lAzhlUJf8BYeU57wE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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