SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4055b5f2b970fbd11ae80c2cda69cbee4996a40c09c73d893c75d5b1353794f8' 
  AND token = 'Qy3kQIwQgtU+Bj9N+7+Q85Ft+35VKBW8vqKufZoAmHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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