SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c702974bf142286599efc16fd909610ef5ce9a5fb5aa572d89a56c560957ea29' 
  AND token = '8kpdADWyAZhnyYbIX48W/9AmK/6McS0Qth20BBEaZ0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}